The former girlfriend of Bolivian president Evo Morales, a senior manager for the local office of a Chinese engineering group, has been arrested in an influence-peddling investigation, the interior ministry said.

“Citizen Gabriela Zapata Montano was detained this morning and is being held” in the jail cells of the police anti-crime taskforce, the interior ministry said on Twitter.

The charges relating to her arrest were not made public.

The arrest comes weeks after local media revealed that the president’s former girlfriend worked for CAMC, a Chinese group that recently won a bid for a major railroad expansion project.

Opposition politicians quickly accused Morales of influence peddling in connection with the $560m government contract.